12v bilge pump to irrigate from a trailer tank?

California · Apr 21, 2009

2manyrocks said:
Usually the [intermittent or continuous] rating is stamped on a plate on the motor.

The only thing I can find is on a tag attached to the cord, in tiny type:
A 3-way manual switch or time delay automatic switch can be installed to address nuisance on/off cycling.
That must mean there is a thermal cutout. But 3-way manual switch???

And also on the tag:
Wire in secondary bilge pump in parallel and install float switch properly before use.
Huh??? I didn't buy this to run parallel with a *real* pump!

It looks like trial and error is the only way to learn if this is going to work in my application.

studor · Apr 21, 2009

California -- no worries -- normally the bilge pump has a redundant backup pump and a float switch to determine when to turn on in the bilge. If you are running in rough water the float switch may cause the pump to cycle on and off without water, hence the three way switch. I think your plan is to stick it in the tank, connect it to 12 volts and let it pump

-- it will work and for your application I am pretty sure that the duty cycle is irrelevant (unless it is so short that the pump is worthless anyway

)

2manyrocks · Apr 21, 2009

Sounds like you've got all the components to start experimenting.

California · Apr 22, 2009

"... all the toys to start experimenting."

I love being retired. I finally have time to do stuff just for fun, like a little kid.

I'll post photos as I learn what works.

California · Apr 25, 2009

If anyone is still following this soap opera ...

I put clips on the tractor battery feeding an ordinary 3 prong outlet. Then I wired the pumps using 14 gauge PC power cords.

Volume is pretty good. The utility pump (threaded inlet and outlet) moves 4 gallons per minute and the bilge pump is double that. Moving up from garden hose to optimum size ( 1 1/8 for the bilge pump) should improve output, and might get the bilge pump's claimed 18 gpm.

My design isn''t perfected yet. I'm losing half a volt at the battery clips (and nothing is warm), a half volt in the 6 ft of PC cord and its twisted wires that the utility pump clamps to, and still another half volt when I put a 25 ft 14 ga extension cord in series between the battery clip outlet and the PC cord. So for the bilge pump I used wire nuts to connect it to its PC cord. This should have less loss. And at the battery I need to bolt the wires to the battery cable lugs.

After I got the bilge pump set up I took it for a test run. This pump fits in the 26 gallon (100 liter) tank, and it empties it in 3 minutes.

I hate to cut up the large tank to put the bilge pump inside. I may water from the front tank and use the utility pump to move water forward continuously while I drive to the next tree.

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studor · Apr 26, 2009

California -- if you switch the bilge pump hose to sump pump hose the volume will go up. I would use a heavy duty two wire trailer connector to connect the pump to the wire to the battery or even use lighter plug and wire in a lighter socket. In terms of putting a whole in the tank, see if you can slip the bilge into any kind of plumbing flange. I thought you might be able to use a hole saw to cut the tank and then have a finished "port" to put the sump pump into rather than just hacking a hole. The next thing is to get some five gallon buckets and make a series of 1/8" holes in the bottom. You put those next to your trees and fill them up to give your trees a more thorough watering.
regards

California · Aug 24, 2009

Progress continues on the ultimate watering system.

I have a 200 gallon flat tank (maximum my 4x8 trailer will carry over rough ground) feeding a 12 volt external pump. This pump runs near continuous replenishing a smaller 25 gallon tank up on top, pumping continually while I am watering and while I drive to the next tree. Thanks Studor for the suggestion to use sump pump hose. I found some inch and an eighth hose off a pool filter which increased output of this smaller pump dramatically.

The top tank contains a fast 12 volt bilge pump. With 4 ft of drop, this dumps 15 gallons into each tree basin in less than a minute. (This is all the same hardware shown in the photos above.)

To distribute 12 volt power I applied stuff I already had - ordinary extension cords (14 ga), and multiple outlet strips for their integral switches. I still need to make a rational control panel.

The next step will be to locate the switches and irrigation hose where I can reach them without getting off the tractor. I also need to make a long watering wand from plastic pipe, so I can reach each tree from the tractor seat.

Thanks everyone for lots of good advice. This really works well.

juandigital · Jun 21, 2011

nice use of a 12v sump pump. They have a TON of uses. Mine keeps my basement dry!

California · Jun 21, 2011

Nice use of a 12v sump pump. They have a TON of uses.

Thanks! I have used this rig a number of times now, and it works great.

I eventually replaced this green output hose with 1.5" shop-vac hose to deliver maximum volume.